In the pancreatic tumour microenvironment, NGF binds tyrosine kinase A (TrkA) receptors, leading to the activation of various downstream signalling cascades, such as PI3K (phosphatidylinositol 3-kinase)–Akt signalling pathway, which contributes to survival of both cancer and neuronal cells51, another one is RAS–MAPK (mitogen-activated protein kinase signalling pathway, which leads to the survival, proliferation and invasion of cancer cells51. Here, NGF is linked to cancer.